Continuous Infusion Ketorolac for Postoperative Analgesia Following Unilateral Total Knee Arthroplasty.

BACKGROUND

Previous clinical trials have demonstrated benefit with the addition of continuous infusion (CI) ketorolac to a multimodal pain regimen in surgical patients. Data following major orthopedic surgery are minimal and conflicting.

OBJECTIVES

To evaluate CI ketorolac use following unilateral total knee arthroplasty (TKA) through assessment of patient-reported pain scores, opioid consumption, and safety outcomes.

METHODS

This was a retrospective, open-label cohort study that included patients undergoing unilateral TKA at a single-center teaching hospital. Participants were categorized into 2 study groups based on postoperative management: CI ketorolac or opioid protocol (OP). The first group received a ketorolac 30-mg bolus followed by CI 3.6 mg/h plus as-needed (PRN) opioids. The OP group received PRN narcotics in a tiered protocol. The primary end point was comparison of median pain scores. Secondary end points included opioid consumption (morphine equivalent units [MEUs]) in the first 48 hours postoperatively, length of stay, and adverse effects.

RESULTS

Of 447 patients screened, 191 were analyzed (CI ketorolac, n = 116; OP, n = 75). Median pain scores were significantly lower in the CI ketorolac group at 48 hours postoperatively (3 [2-4] vs 3.5 [2.5-5], P = 0.033). Cumulative MEUs at 48 hours were significantly lower in the CI ketorolac group (33.9 ± 38.5 mg vs 301.6 ± 36.6 mg, P < 0.001). Patients in the CI ketorolac group experienced less respiratory depression (5.2% vs 25.3%, P < 0.001) and less naloxone administration (0% vs 8%, P = 0.002) compared with the OP group. Other adverse effects were similar among groups.

CONCLUSIONS

Postoperative CI ketorolac improved pain control while reducing opioid consumption and adverse effects.